Telephone-exchange apparatus.



No. 854,203. PATENTEDMAY 21, 1907.

0. D. moons.

TELEPHONE EXCHANGE APPARATUS.

. APPLIOATION FILED M3,. 1905.

W'd-Zn as 5 e6: ,Zzrenior:

UNITED s'r rns PATENT orrron.

CLAUDE D. ENOOHS, OF LA CROSSE,

BERGER COMPANY, A CORPORATION OF WISCONSIN.

TELEPHONE-EXCHANGE APPARATUS.

Ira-854,203.

Specification of Letters Iatent.-

Patented May 21. 1907.

Application filed April 24, i905. .Serial No. 257,051.

To all whomit may concern:

Be it known that I, CLAUDE D. ENOCI-IS, a

7 citizen of the United States, residing at La part of this specification...

My invention relates more particularly to means for causing the subscribers transmitter 'to operate more eliiciently and effectively in the transmission 'of sound waves over the line circuit. v

In the operation of telephoneinstruments connected with central station batteries, the

resistances ofthe multitudinous subscribers line circuits vary widely and in consequence there IS a difierence 1n transmission of cur rent from the source of supply, and when it Qis found necessary to boost the central office 'battery/to-such an extent that the transmission from the station on a long-subscrib rs loop is effective, the transmitters at the subscribers stations'on other loops of low resistance are often destroyed ormateriallydamaged from theiheavy current which they these The object of my invention is to overcome defects in a simple and el'licient manner. 4 i

In the accompanyingdrawing is shown a diagrammatic view of part of a simple tele- "phone eXchange system equipped with my invention.

A represents the hne circuit, B the subscribers set'having a transmitter C connccted therewithand D the line jack at the central station, all of said parts being of ordinary construction.

Atthecentral. station are the usual an-- swering and call plugs or cords E and F. The conductors 2 and 3 of the answering plug E are connected with windings 4 and 5 of repeating coils. The opposite terminals of said windings are connected with a condenser 6 is bridged between the terminals of the repeating coils, said terminals and each pole of the battery is connected in series with a steadying resistconnected with a battery G. A.

and each loop between- I have chosen to to be hereinafter more ance (II and I) or what term a ballastfi fully described.

ing windings 7 and 8 of the repeating coils are condenser 9 and in series with loops 10 and 1.1 of the call plug. Each ballast H and I contained in the opposite conductors of the cord plug circuit at the central o'llice, as described, is in the form of a conductor 12, made of fine iron wire or other sultable material, ber 13, which may or may not contain an incloscdin a sealed chaminert gas, as preferred. .The ballast conductor decreases 1n conductivity as 1ts temperature rises, and in case the line has a high true resistance the ba last receives a small amount of current and its resistance ,WISCON SIN ASSIGNOR TO THE VOTE- T he res )ective co-o )erat- Will be comparatively low and vice versa.-

The subscribers transmitter case will receive the highest possible current on a line of any length and produces the best possible transmission, and in the latter case .the added current will increase the resistance of the ballast to such ail-extent that the subscriber's transmitter will not be injured by excessive current. ber asdescribed and a fine iron-wire conductor therein, I have found that the heat produced by the current passing through in the former By using a sealed chamsaid conductor is not materially radiated and the corrective resistance and temperature of v the ballast are thereby made extremely sensitive. In the practice of my invention it is possible to boost the central o'lhce battery to-substantially any extent desired, for the ballast automatically regulates and protects the subscribers transmitter from injury by ex cessive current. The ballast acts in the manner of steadying the resistance of the cir cuits to which it is connected, as described, and has a large positive temperature correction, which is alwaysinnnediately available, and the variation of voltage in the line circuit is regulatedto a nicety. i

" It is not always necessary to connect the ballast with the cord circuit, as above described, for it may be connected With any suitable part to effect the results in the use of my invention it is obvious that current from the battery in the cord circuit may be fed over a relay winding in place of the repeating coils (as shown) or that current stated, and

' without departing 'vention to effect the results set forth, and I sistance thereof.

- operate with said jack-at the central station,

- operating with said line circuit, and a-ballast adapted ing a transmitter included in said circuit, a

.ing a transmitter included in said circuit, a

and a ballast connected with said cord plug the transmitter battery may be fed I over a relay included in the line circuit Without varying from the principles which I have applied. While I have shown one formof ballast, it is obvious that other forms may be used from the spirit of this in- 2. Telephone exchange apparatus, com prising a line circuit, a cord plug circuit 00- to be included in said circuits, for the purposes specified. j i

3. Telephone exchange apparatus, com'-' prising a line circuit, a subscribers set hav cord plug circuit at th central station adapt-' ed to co-operate with said line circuitpasource of electric current included in said cord; plug circuit, and a ballast connected with said cord plug circuit, for the purposes specified.

'4. Telephone exchange apparatus, 'comprising a line circuit, a subscribers set haviline jack, a cord plug circuit adapted to 00- a battery included in said-cord plug circuit,

circuit, for the purposes specified.

. 5.- Telephone exchange apparatus, 'com-' prising a line circuit, a subscriber's set.hav' ng a station adapted to co-operate with said jack, a battery and repeating coil included in'said transmitter included in said circuit, aline jack, a cord plug circuit at the central.

cord plug circuit, and a'ballast connected in series with said repeating coil and battery,"

for the purposes specified.

6. Telephone exchange apparatus, comprising a subscribers circuit, aline jack connected with said circuit at the central station, l p a cord plug circuit .adapted to co-operate With said line jack, a battery connected with the conductors of said cord plug circuit, and

a repeating coil and ballast connected in series with each ofsaid conductors.

7. Telephone exchange apparatus, comprising connected with said circuit,-a cord plug circuit adapted to co-operate With said jack at the-central station,

a source of current supply connected with said cord plug circuit,

a subscribers line circuit, a line jack and a, ballast connected in series with each conductor ofsaid cord plug circuit.

8. A telephone system having associated therewith line circuits of divers resistances, a telephone set for each line circuit, a cord plug circuit, a common source ofcurrent supply, and a ballast adapted to be-included in said circuits, for the purposes specified.

'9. A telephone system,'having associated therewith, line circuits of divers resistances, a telephone set for each line circuit, a cord plug circuit, azoommon source of current supply, anda'ballast ada tedto be associated with said circuits, for t e-purposes specified.

10. Telephone exchange apparatus, comprising a subscribers line circuit A, a sub- ;scribers set cluded in said circuit, a line jack D connected, With said circuit, a cord plug E at the central station adapted to co-operate with said line tors of said cord' plug, a repeating coil and ballast connected in series with each of said conductors, and aicondenser 6 in multiple with said conductors.

B having a transmitter C in-- 8 5 jack, abatter y G connected with the conduc- In testimony whereof I have signed my name to this specification in the presence of. twoisubscribing Witnesses.

CLAUDE. D. ENoc'Hs.

i Witnesses:

M. R: BEEGER, V. BOLEY Y 

